title: Oligosaccharides at individual glycosylation sites in glycoprotein 71 of Friend murine leukemia virus.
abstract: Glycoprotein 71 from Friend murine leukemia virus was digested with proteases and the glycopeptides obtained were isolated and assigned, by amino acid sequencing, to the eight N-glycosylated asparagines in the molecule; only Asn334 and Asn341 could not be separated. The oligosaccharides liberated from each glycopeptide by endo-beta-N-acetylglucosaminidase H, or by peptide-N4-(N-acetyl-beta-glucosaminyl)asparagine amidase F, were fractionated and subjected to structural analysis by one- and two-dimensional 1H NMR, as well as by methylation/gas-liquid-chromatography/mass-fragmentography. At each glycosylation site, the substituents were found to be heterogeneous including, at Asn334/341 and Asn410, substitution by different classes of N-glycans: oligomannosidic oligosaccharides, mainly Man alpha 1----6(Man alpha 1----3)Man alpha 1----6(Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4GlcNAc beta 1----, were detected at Asn168, Asn334/341 and Asn410. Hybrid species, partially sialylated, intersected and (proximally) funcosylated Man alpha 1----6(Man alpha 1----3)Man alpha 1----6 and Man alpha 1----3Man alpha 1----6 and Man alpha 1----3Man alpha 1----6(Gal beta 1----4GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNAc beta 1----4GlcNAc beta 1----, were found at Asn12, as previously published [Schlüter, M., Linder, D., Geyer, R., Hunsmann, H., Schneider, J. & Stirm, S. (1984) FEBS Lett. 169, 194-198] and at Asn334/341. N-Acetyllactosaminic glycans, mainly partially intersected and fucosylated NeuAc alpha 2----3 or Gal alpha 1----3Gal beta 1----4GlcNAc beta 1----2Man alpha 1----6(NeuAc alpha 2----6 or NeuAc alpha 2----3Gal-beta 1----4GlcNAc beta 1----2Man alpha 1----3)Man beta 1----4GlcNac beta 1----4GlcNAc beta 1---- with some bifurcation at ----6Man alpha 1----6, were obtained from Asn266, Asn302, Asn334/341, Asn374 and Asn410. In addition, Thr268, Thr277, Thr279, Thr304/309, as well as Ser273 and Ser275, were found to be O-glycosidically substituted by Gal beta 1----3GalNAc alpha 1----, monosialylated or desialylated at position 3 of Gal or/and position 6 of GalNAc.
authors.affiliation: Biochemisches Institut am Klinikum der Justus-Liebig-Universitat, Giessen, Federal Republic of Germany.
authors.forename: R
authors.initials: R
authors.lastname: Geyer
authors.forename: J
authors.initials: J
authors.lastname: Dabrowski
authors.forename: U
authors.initials: U
authors.lastname: Dabrowski
authors.forename: D
authors.initials: D
authors.lastname: Linder
authors.forename: M
authors.initials: M
authors.lastname: Schlüter
authors.forename: H H
authors.initials: HH
authors.lastname: Schott
authors.forename: S
authors.initials: S
authors.lastname: Stirm
mesh_terms: D000595:Amino Acid Sequence; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005622:Friend murine leukemia virus / Q000032:analysis*; D006020:Glycopeptides / Q000302:isolation & purification; D006031:Glycosylation; D006378:Helper Viruses / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000302:isolation & purification; D010449:Peptide Mapping; D015682:Retroviridae Proteins, Oncogenic / Q000235:genetics / Q000302:isolation & purification*; D012689:Sequence Homology, Nucleic Acid; D014759:Viral Envelope Proteins
chemical_list: D006020:Glycopeptides; D009844:Oligosaccharides; D015682:Retroviridae Proteins, Oncogenic; D014759:Viral Envelope Proteins; C038947:glycoprotein 71, Friend murine leukemia virus